Sorry if this has been addressed in another thread, however several search's found nothing relevant.As a seasoned 737NG (600/700 release) driver, I recently purchased the 800/900 add-on, and have noticed some new problems with the FMS. First problem although it's more of an annoyance is the numeric keypads bottom row is not mapping where the mouse is positioned over. Specifically when I move over the [0] key, it inputs an 8, however if I click at the very bottom of the button, I get the 0. I thought it might be my video, but this 'mapping' is isolated only to the numeric keypad as every other button maps properly.Second problem is a bit different regarding the operation of the FMC. Before the upgrade I could program a flight (very light weight) to FL450, however since the upgrade the FMC gives me the error that FL410 is the maximum. Okay, so I depart let VNAV level me to FL410, and then disengage VNAV and finish my climb to FL450. As i near my TOD I manually descend to FL410 and set the MCP to match FL410 which is programmed in the FMC anyway as I couldn't change it anyway. Now no matter what I do I cannot re-engage VNAV as it just display's the error "CK MCP ALT". It's a bit frustrating because I like the enhancements to the radio panel, and the clock.If anyone has any suggestions I would be very appreciative.Thanks,Gerry H

The CDU keyboard is mapped for a 4:3 aspect such as 1600x1200. The alternative is to drag the CDU window.All these years I thought the 737 max cruise altitude was FL410, I believe that is as high as any operators fly her.

The maximum cruise altitude for the 737-900 is FL410. This is because it has an automated cabin pressurisation system which drops the cabin altitude pressure differential when up at that altitude (kicks in at 38,000 feet if I recall correctly). The point of reducing the pressure differential, is so that the fuselage is not subjected to as much stress, and so get less fatigue. It is one of the reasons why the 900 is certified for the extended number of cycles that it is.The BBJ versions differ a little bit in this respect and do pressurise differently, to allow for increased passenger comfort (as you would imagine on a posh BBJ). This is deemed acceptable since they are generally not utilised as heavily as airliners, but it is unlikely that an airline would sidestep that altitude limit, as it would overstress the airframe, and reduce the service life of the aircraft.Al

Thanks for the answers gents, however as this is just a sim should I decide to take her above the 'certified ceiling' that's the pilots purgative not the aircraft. What puzzles me is this 'constraint' was introduced when I added the 800/900 add-on, and I cannot find any cfg file that modified it (hard-coded dlls perhaps?). So I uninstalled the add-on but then my PMDG aircraft would start dark with no ability to control the overhead.Frustrated, I used the 'uninstall utility' to completely remove PMDG from FS9, then FS9 wouldn't start at all due to a 'configuration error' as it was still looking for my PMDG. To add to the frustration, after a complete FS9 uninstall, FS9 complained about the same error and shut down.This time I've completely blown away my FS folder (and no I don't use the default directory of "C:\Program Files..."). As I'm in the process of a brand new installation of FS9 (just to see if the damn thing even starts) I cannot comment on progress so far.It's too bad that the 800/900 add-on did this, as I don't plan to reinstalled it again if it's going to constrain me to what the computer wants.Cheers,Gerry Hattendorf

Make sure you clear the Documents\Flight Simulator Files folder of any saved or left over flights. That's probably why FS9 was looking for PMDG even after an uninstall.JoeM

I have a question for the 737-8/900 series. I'm climbing to the opt altitude and I let it sit there for a while to wait for the next opt altitude in my direction to show up. I've noticed that the OPT/MAX altitudes are within just a couple hundred feet of each other. Typically in the bigger jets you have an OPT of say 315 and a max of 346, mine right now is showing an OPT/MAX of FL311/FL333! What is going on with this feature? I was doing a long cross country with my takeoff 400 lbs under max gross and never made it above FL330 because when I tried to update the CRZ page to FL330 it went right to the DES page and I still had 2000 miles to go!!! Was there an update to the 800/900 that I did not see? Also, is there an install file that would allow me to install the 800/900 without having to do update installs after???MattProud owner of: PMDG 737-6/7/8/900, 747, MD11

The bigger jets have a larger proportional weight in fuel than the 739, step climbs in this family are usually not required for economics. Don't know why the CDU displayed DES, maybe the segment you were on was a long one that extended to within a couple of hundred miles to the destination?The download installers (at pmdg downloads) are comprehensive, if you install them they will include all prior updates.

The bigger jets have a larger proportional weight in fuel than the 739, step climbs in this family are usually not required for economics. Don't know why the CDU displayed DES, maybe the segment you were on was a long one that extended to within a couple of hundred miles to the destination?The download installers (at pmdg downloads) are comprehensive, if you install them they will include all prior updates.

I'm actually flying the 737-800 right now and I've noticed it has a bigger spread (OPT/MAX = FL353/FL371) than the -900. I find this rather unusual for the 900 though. Thanks for the reply. One more question, where are these downloads? I've got some files that are rather big for my aircraft and some include updates and they have to be installed in a certain order!!! Do the downloads you are talking about do away with the updates and installing in just the right order?Matt

"(at pmdg downloads)" ... go to the pmdg web site, follow the downloads link to service updates.